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<H1>SMSW -- Store Machine Status Word</H1>

<PRE>
Opcode      Instruction     Clocks          Description

0F  01 /4   SMSW r/m16      2/3,pm=2/2      Store machine status word to EA
                                            word
</PRE>


<H2>Operation</H2>

<PRE>
r/m16 := MSW;
</PRE>

<H2>Description</H2>

SMSW stores the machine status word (part of CR0) in the two-byte register
or memory location indicated by the effective address operand.

<H2>Flags Affected</H2>

None

<H2>Protected Mode Exceptions</H2>

#GP(0) if the result is in a nonwritable segment; #GP(0) for an illegal
memory operand effective address in the CS, DS, ES, FS, or GS segments;
#SS(0) for an illegal address in the SS segment; #PF(fault-code) for a page
fault

<H2>Real Address Mode Exceptions</H2>

Interrupt 13 if any part of the operand would lie outside of the effective
address space from 0 to 0FFFFH

<H2>Virtual 8086 Mode Exceptions</H2>

Same exceptions as in Real Address Mode; #PF(fault-code) for a page fault

<H2>Notes</H2>

This instruction is provided for compatibility with the 80286; 80386
programs should use <A HREF="MOVRS.htm">MOV</A> ..., CR0.
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<B>up:</B> <A HREF="c17.htm">
Chapter 17 -- 80386 Instruction Set</A><BR>
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